


Do you want to do some stretching?

by TheSinfulPen



Category: Red Velvet (K-pop Band)
Genre: F/F, Futanari, Girl Penis, Gratuitous Smut, Implied/Referenced Cheating, Other, Shameless Smut, Smut, Unrealistic Sex
Language: English
Status: Completed
Published: 2020-04-02
Updated: 2020-04-02
Packaged: 2021-02-28 19:13:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,685
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23452255
Author URL: https://archiveofourown.org/users/TheSinfulPen/pseuds/TheSinfulPen
Summary: Bae Joohyun was a faithful married woman who was growing tired of her husband's lack of tact (well, just lack of everything).So when the offer for a good stretching came to her in the hands of a charming young trainer, Kang Seulgi, she could not decline.
Relationships: Bae Joohyun | Irene/Kang Seulgi
Comments: 7
Kudos: 196





	Do you want to do some stretching?

**Author's Note:**

> Posted originally on AFF, but due to recent complications on AFF (and to have a full library here) I've put the story here!
> 
> This fanfiction contains slightly unrealistic sex scenes, since this is an experimental side I am trying.  
> Also, do I need to mention Seulgi's special gift? Please, if you're not fond of futanari, please look away.

She was one to work out and keep her body healthy and beautifully functioning. At first it wasn’t because of her appearance, she just did it because she wanted to stay healthy. However, as many more people would relish her body, she would find herself doing it because she loved to look like that and keep people’s attention to her--even if it was briefly.

It did well enough, bringing her a lot of good candidates to marry, but she reserved herself for the perfect one. Well, what she thought was the perfect one. Still, she was enchanted quite easily with a name none of you care about, a wallet which you would love to see (and have) and a secure future.

He was someone who was up to par with her business life, he was perhaps a slight bit more successful but only because he screamed the loudest.

Ultimately, she was leading a successful life as a business woman as well as a wife.

Well, almost successful.

“May I help you?”

Was the first thing she heard when she came back to the gym after New Years, when the staff got a complete switch; some got fired, some got hired. Joohyun, pale, short and very intimidating, looked up from her bag and saw a lanky, slightly taller woman. She wasn’t muscular, but she had a great figure on her own.

Joohyun cocked her eyebrow up in interest before she smiled. Then, the conversation began as they went through a standard working out routine.

Sure, it was exhausting, but talking and conversing with her trainer was worth the while. She could keep a great conversation, she was genuinely interested with what Joohyun had to say, she laughed and seemed to genuinely enjoy the time, and her eyes didn’t oogle too far down from the pale woman’s doll-like face. Honestly, they did wander a little, but it was more of a natural response to being in such a close proximity with the most desired woman in the entire gym.

All the boys had the same fantasies in mind which was to fuck Joohyun, but none of them were smart enough, had the personality of a dying sloth, and were cowards.

Sure, they wanted to fuck a married woman, but they weren’t brave enough to deal with the consequences of what could possibly happen if caught.

Joohyun herself was flirting with that idea, but to give these idiots the satisfaction of bragging with their friends that she was oh so attracted to him to cheat when in reality she was just bored out of her mind and desperate? Not in a million years.

The business woman had not only pride but a sense of self-respect. The situation really needed to be presented with a silver--no, golden platter for her to even consider the opportunity. Truth be told once a man did come about, a black young man with eagerness of a child in a playground but the stubbornness of a taurus when it came to getting what he wanted.

He was charming at first, then he just turned annoying, wishing to prove his superiority with every man in the gym and really just pushing the woman’s buttons and pressuring her into it. At that point, the throbbing between Joohyun’s legs just died and she moved on, ignoring that man completely until he just no longer appeared.

But the truth was, she was bored out of her mind with her husband who was absent, first of all, and secondly just an absolute prick. It was all about his pleasure, it was never about Joohyun. Did he come home late? Too bad, he had a headache and wanted to go to bed. Was he early? Probably his squeeze got annoyed of him so he took it off on Joohyun, who just laid there motionless and bored out of her mind. Masturbation? He got upset.

“Am I not pleasing you?” He said.

“No,” Joohyun instantly replied.

He ignored and insisted it was her fault for not being a better wife.

Hell, she was glad to have her tube ties and not give him any kids; she was also glad she didn’t tell him ANYTHING about it.

So, there she was. Briefly, she was on the lookout for a potential affair, a man worth her time--hell, even a woman who was worth her time, though her lean was more towards men. But nothing came, so she gave up on trying to look.

That’s when she found what she was looking for, in the least expected moment, in the least expected person.

It was in the form of a foxy-eyed trainer.

“Do you want to begin stretching?”

  
  


**

The eager chatters around the gym and even around the neighbor were the first to talk about little Kang Seulgi, who looked innocent enough to never ever be accused of murder even if she did in fact commit the crime. It was bizarre, being new to this place after having her and her husband be transferred to this slightly smaller but equally busy city.

Joohyun could’ve been ABSOLUTELY fooled for a long time if she hadn’t heard people speak.

Turns out Seulgi had done a lot of the girls in the gym! Not more than once, however, as they were affairs, but the girls were satisfied and pleased even if they did not go for the second round.

It did come to Joohyun’s mind. Seulgi was incredibly charming, too charming to be single. Maybe she wasn’t one to date people, maybe she just wanted to have fun but one thing's for certain and it was that Kang Seulgi never had sex with a woman more than once even if the girls were fond of her.

It was certainly intriguing to Joohyun. She didn’t look like she was flirting with her to be a new fling, but rather just being friendly and getting to know the pale business woman well.

There was not an ounce of flirting or malice to her, she was just friendly and doing her job.

Still, Joohyun dug around the clubs and bars in the nearest vicinity and got herself a group of friends who were eager to talk about all their hookups and other topics.

What she ended up finding out besides lucking out from the black gentleman from before (he, too, was like her husband--intensely selfish and absolutely boring), was that Seulgi had a knack for… pleasing her partners.

Five orgasms, one recalled, just in the fucking section--though she seemed unsure, there were perhaps more than that. It had to end because she was very tired and unable to go on.

It was a lot of numbers for a normal affair, it intrigued Joohyun. She wondered how someone could last that long and not get exhausted. She almost wanted to dig further down, but not knowing was turning her on, making the anticipation build.

“Stimulating all of that is quite the job!” One of them said, sipping into her bourbon before going back to stirring it around. “If you know what I mean.”

“Oh, for certain,” the other one laughed.

No, she didn’t understand. It was perhaps the crowded bar and the obnoxiously loud music, but she could not understand the subtle hints.

What did she mean by all of that?

It took only a moment or two before Joohyun’s friends understood her confused and frowny face. Finally, they spilled the beans about what was so magical about Seulgi.

Joohyun blinked and her eyes widened. She shook her head rapidly and exclaimed. “No way!”

  
  


With this new information, she started to be more aware of Seulgi and her body language, most especifically, her gift; hidden somewhere in her baggy sweats that she always brought to work. They were always black and it seems that she made sure conceal it as best as she could, and no one would notice unless they were actively looking for it..

For Joohyun’s surprise, she wore gray baggy sweats and my god it was glorious.

  
Every head turned to see Seulgi--well, the women’s head, the fellas were possibly just jealous or curious. Joohyun herself was drawn to looking at it but quickly acted out as if it was nothing through the entire working out routine. Except for the bench presses, that’s when her eyes couldn’t look away, and when Seulgi noticed her staring.

“Alright, that’s good!” Seulgi encouraged Joohyun as she did her bench presses.

She was right there above Joohyun’s head, her crotch was so close yet so far. Joohyun was trying to concentrate on them, but the moment she looked upwards was the moment she gasped.

It was protruding and pretty noticeable now, especially since she was technically under that bulge..

How did she not notice before? She must’ve been very distracted by Seulgi’s chit-chat and her hardwork that she was blind to it.

Seulgi noticed this, she noticed her staring in awe, almost with her mouth open. Seulgi even blushed and Joohyun swears that her cock even twitched in that moment, out of excitement perhaps..

After that, she cleared her throat and both acted like this had never happened, even if the aching between Joohyun’s leg was becoming more and more demanding.

  
  


**

“Why aren’t you moaning?”  
  


Asked her husband for the nth time as Joohyun felt the most bored. Not even math class in sixth grade could surpass this. She didn’t really want to be there, and she was having nothing but constant waves of regrets with every dull thrust of her husbands.

Good god, why couldn’t that monstrous throb between her legs appear NOW.

The ceiling was far more entertaining as her husband moved, ramming her like a jackhammer of some sort. He clearly watched too much porn movies and thought this was the way to go, or maybe that was the way he got off.

Truthfully, Joohyun would’ve helped him nicely and told him what she liked if his pride and ego wasn’t so important to him. He refused to listen and there’s no results in talking to a wall.

So, to pass the time, she wondered about Seulgi, about that big smile of hers… about that huge cock.

Yes, how would it feel to have it inside of her? To have it just brush her needy walls with utmost care. It probably felt like heavens, after her second orgasm or something. Who knows, maybe even more than that.

She was starting to feel a nice tingly sensation in her pussy, she was starting to feel warm, and pleasure. A few soft whines left her lips instead, still drowned by her husbands grunts that seemed to be growing louder.

Joohyun was starting to feel something--something good--, but it was too late as her husband had already reached his climax and stopped thrusting altogether. She tried to move a little and get something, but he pulled away and laid on his side of the bed.

Story of her life.

It was frustrating enough that she never really had that much pleasure from any of that, but the fact that now that she was getting something (thinking of another person, but still) it finishes early? That’s the very worst. It leaves her even hornier and needier than ever before.

While her husband snores, she’s in the bathroom cleaning herself from that boredom trip. Her mind was on one thing only: Seulgi.

She was determined. The following day she was going to go to that gym as early as possible and talk to Seulgi, one way or another. She was going to get Seulgi and fuck her.

  
  


The gym wasn’t even open by the time Joohyun pushed through the doors with nothing in her hands but air and determination to stroke Seulgi’s massive cock with all her energy. Obviously, Seulgi noticed and looked back at the door, dumbfounded with dumbells in her hands before she arranges them where they were supposed to be.

She wasn’t wearing gray sweats, but thank god. If she were, Joohyun would’ve jumped to her in an instant.

“Oh, Mrs. Park--.” Seulgi began, stopped by Joohyun’s exasperated look.  
  
“I told you to call me Joohyun, and definitely not Mrs. Park--Ms. Bae if you wish,” the pale woman insisted, accidentally sounding like everything but friendly.

Seulgi visibly gulped, nodding. “Right, I’m sorry… it’s habit.”

Joohyun nodded and smiled a little to try and get her to loosen up a little before she looked around. “Are you alone?”

The personal trainer looked around as well, soon shaking her head. “No, other trainers are around, why?”

Joohyun deeply inhaled and spoke softly. “I heard of you and your gift.”

Seulgi froze for a moment, nodding slowly, this coming to no real surprised but catching her off guard. “Okay…”

“And I’ve been nothing but a toy for my husband for months now. I want--no, I need a good fuck.”

“Y-you think I’m adequate for that?” Seulgi softly replied, gasping in surprise when Joohyun groped her bulge firmly and with assertiveness. “L-Lady…”

“Don’t be so formal,” Joohyun groaned, letting her face get really close to Seulgi’s, just inches away from her lips. “What do you say, Seulgi? I really need it.”  
  
“B-but you’re married,” she gasps, feeling that Joohyun was now concentrating in stimulating the tip of her cock.

“He’s a loser, Seulgi. Please?”

Seulgi gulped and thought about it. Like… really thought about it, despite having her eyes travel down and below as she thought. At the end, there wasn’t much to think as her cock was already hardening and hard to pass off.

And with Seulgi’s special needs, she couldn’t refuse.

“Then, do you want to begin stretching?”

  
  


**

  
  


Joohyun didn’t know that stretching was literally what that meant.

Stretching.

There was Seulgi’s massive cock, the tip buried inside of Joohyun’s pussy, stretching it to fit the size that’s to come. It was so hard, so big and thick, it would put other guys at the gym to shame for damn sure. Sure they had good bodies, but they didn’t come close to Seulgi’s ability to love on someone, her size and just her sex appeal.

“Oh, god! Oh, god!” Joohyun moaned out loudly, holding onto Seulgi’s shoulders as she bounced on the cock, slowly but surely getting more of that cock inside of her.

Seulgi had dragged Joohyun to the empty locker rooms right after they’d agree on this escapade, instantly letting Joohyun know why a lot of girls talked about her. The way she kissed her lips and her skin was one of an authentic and eager lover, so willing to please and ready for the action, she had the passion that many of their flings lacked. She wasn’t a porn star or an expert by any means, but she was willing to listen to feedback, willing to improve all the time and she didn’t let that get to her head or to her ego.

Joohyun’s pussy was so hot and throbbing that they had skipped almost all the foreplay. Seulgi instantly went down on the pale business woman’s pussy, being so close to ripping the clothes apart before the hands of a calm Joohyun helped her get rid of the layers. Without interruptions or barricades, Seulgi’s lips dove right in and pleased the woman like her husband wouldn’t--no, like he couldn’t.

Her first orgasm came with the oral, of course, having her tongue buried so deep and wiggling around so eagerly against her spot. She resisted a little to the orgasm, afraid that it would stop so soon, but it didn’t. Seulgi moved on from her cavity and instantly gave loving to her clit--often ignored by most people, even her previous lovers. She flicked her clit with her tongue, caressed it in circles, drew all kinds of shapes and letters onto her clit; the second orgasm came at the very last letter, yanking a louder moan from the now-pleased wife.

The bench wasn’t exactly ideal, and Joohyun was almost declining the offer to do it here, but there she laid: on her back, legs spread, and desperately trying to find something to cling onto, trying not to rip Seulgi’s hair away as she sucked on her clit and her fingers pushed the walls for accommodation.

Joohyun had come to Seulgi expecting one or two at best, or some disappointment, but she was glad she was exceeding in pleasing her. Seulgi took pleasing her to another level, she took her job seriously as her eagerness never seemed to die off at any moment. In no time after, Joohyun had her third orgasm, exploding into a long and loud cry for Seulgi, whining her name out without a single bit of shame.

She was cheating, oh but who fucking cares?

Then, the most anticipated moment of that morning. Seulgi had taken the bench and laid on it, fishing her huge cock out. Joohyun did her very best, getting the tip into her mouth and perhaps further in, her hands endlessly stroking that massive cock with definite lust and hunger.

She wanted to reciprocate to Seulgi, giving her as many orgasm as if it was possible, but Seulgi declined by pulling her head away after a while and insisting she got in position.

Joohyun didn’t decline, of course, but she warned. “Oh, Seulgi, I don’t think I can take all of that.”

“Don’t worry, I know you can.”

Now, with the tip claiming its place inside her pussy, the rest followed, almost getting half way before stopping. Joohyun’s walls were offering resistance, or maybe they weren’t used to something so thick and massive--like, at all--but it wasn’t long before her walls hugged and got accustomed to that cock that was now pumping in and out of her.

It wasn’t even halfway in, but the thickness was driving her crazy, it was hitting all the right spots; the speed, despite being moderate, was inching her closer and closer to a bigger orgasm than before.

“Fuck, oh fuck! It’s so thick, Seulgi. I’m gonna come so quickly,” Joohyun desperately gasped out.

Seulgi, who was grunting and whining and bucking her hips almost in an erotic trance, nodded, barely able to speak out. “Come for me, baby.”

Joohyun was squeezing that cock with her walls in pure bliss, and she felt even more of it get within her pussy, pushing her limits and feeling so turned on that her limits were being tested that way. She rode her orgasm with Seulgi’s incessant--but rather careful--thrusting and instantly felt horny and aroused to continue forth without a break.

The question started to roam as she flopped down on top of Seulgi, her pleasure starting back up immediately.

Why wasn’t Seulgi coming? With this kind of friction and with her walls clenching like that, she was sure to have her own orgasm! But nothing happened.

Seulgi’s hands remained on her ass as she continued to ram that cock deeper inside, her groans and grunts getting louder and more animalistic. Joohyun could sense Seulgi was starting to get hungry for more, hungry for her own orgasm, wanting to feel her cock coated and hugged tightly by those walls of that small pussy of hers.

Said grunts were overshadowed by Joohyun’s incoherent moans, gasps and words all strung together haphazardly.

“Oh my fucking, oh my fucking, my god, Seulgi! You’re so thick!”

“You’re so tight, but you’re almost there, baby. You can take it,” Seulgi moaned out, tossing her head back and hugging Joohyun’s body closer, staring into her eyes with her lustful foxy ones.

Indeed, the cock was getting further in and starting to hit spots that Joohyun couldn’t reach normally--whether with her hands or with her husband’s pathetic excuse of a cock--hitting them again and again without fail. The moderate speed soon became faster, slightly rougher by nature.

It was impossible to hold herself back again, Joohyun was already so sensitive and needy from her previous orgasms, that she was quick to have another one, burying her face against Seulgi’s neck and holding onto her shoulders, clawing at them as her pussy expelled more juices down Seulgi’s massive cock.

Again, her walls clung and sucked that cock in with every wave of her orgasm but not a single drop came out of Seulgi. And in that moment of bliss, Joohyun understood, finally getting all the cock inside of her without problems, feeling it fill her up to the very brim.

The position changed to Seulgi on top and Joohyun against the bench, staring into each others eyes as Seulgi’s savage thrust and long strokes. It was wild, rough, just pure lust. In the moments where Seulgi’s cock wasn’t inside of Joohyun, she whined and pushed her hips to let the tip go in, and in the moments it was inside of her she cried out so loudly for Seulgi that she even forgot for a moment that she was married, only remembering it briefly when she tried to cling onto Seulgi’s forearm, the coldness of the wedding ring brushing against her lover’s skin.

The public scenario and the fact that she couldn’t stop screaming Seulgi’s name made it all the more exciting, it threw Joohyun over her sixth orgasm as Seulgi now held her hips and pushed her against her thrust, burying herself even deeper, her full balls slapping and pressing against her ass now, the delicious sound echoing all over the locker room like with her moans. She lavished in that explosive orgasm and quickly got herself ready for the next one, unable to stop feeling that overwhelming pleasure and even begging for it not to stop.

Then, Seulgi carried her and fucked her standing, making her bounce on that cock and really bury it deep inside of her. Joohyun clung and hugged Seulgi’s head closer to her, finally able to hear those soft grunts and moans that were overshadowed with louder cries of pure pleasure. They sounded amazing, so Joohyun tried her best to drown her own voice to listen to her but to no avail.

The seventh orgasm, another myriad of juices coming down Seulgi’s cock and almost dripping down to her balls. Joohyun’s limbs were starting to lose strength, her voice not too tired to continue screaming out for her. She was so sensitive now that she felt Seulgi’s veins in her cock brush against her spots more and more, the warmth further engulfing that beast.

“A-are you tired?” Seulgi asked as she slowed down her wild pace, her thrusting becoming smoother and more relaxed.

Joohyun, who was panting heavily despite doing nothing, shook her head rapidly. She understood why she was asking, she understood why she wasn’t coming yet--she also understood why she didn’t get a woman more than once.

They could not please Seulgi, because they ended up too tired to continue, too satisfied to even want to have sex again, it was perhaps too much work, too dangerous to the woman who could not be able to take it..

“No, no, please, give me more,” Joohyun begged, cupping Seulgi’s cheeks. “I want more.”

That was true. She was still too turned on and horny to not get another one, she needed more than that. From all those times without proper pleasure? She definitely needed more than seven orgasms.

Seulgi’s eye sparkled with newfound determination, going at it again, pinning Joohyun against the locker and really pushing her cock as deep as possible, thrusting as fast and roughly as she could while Joohyun continued to cry out for her, the lockers slightly moving at the bestial movement.

“Yes, Seulgi, yes! Fuck me, use me as much as you need, fuck me until you come!”

Eight orgasm came shortly after and the position changed.

Seulgi let Joohyun down on her feet but lifted her leg over her shoulder and continued to brutally pound that small pussy that was taking such a monster cock. It was so wet and sticky, the slapping and wet noises becoming more prominent. Joohyun was smiling a little now, giddy with all the pleasure given to her, biting her lower lip and in some sort of trance.

It has been such a long time since she felt all the tense feeling of her body dissipate, feeling so aloof. She had no regrets, even if she felt a bit dirty for being with a woman while she was married. But for Kang Seulgi? She’d do anything.

“Joohyun… I can feel it, I-I can feel myself getting closer!”

Joohyun didn’t speak, busy being pounded like she should’ve been for a long time. Instead, she reached back and caressed Seulgi’s head. “Yes, fuck, yes!” She merely said, almost encouraging her to keep going but then she suddenly stopped.

The position changed one more time, doggy style right there in the bench. Joohyun’s torso laid on it but her lower half was being lifted by Seulgi, who was now back to her incredibly delicious thrusting. Joohyun hadn’t noticed, but she had a movement to her thrusting. It wasn’t just jackhammering dry (although, even then it’d be hotter than her husband’s) but Seulgi had a certain luscious movement to her thrusting, it made everything all the better for Joohyun.

One thing she did notice was that now Seulgi was moaning louder, higher in pitch and almost competing against Joohyun’s incessant moans. Her cock was getting thicker inside of her as her pussy was getting tighter and tighter with her orgasm approaching.

Joohyun’s eyes rolled back a little before closing them tightly, pressing her cheek against the bench as she drooled, feeling Seulgi’s balls slam and slap against her clit and pussy again and again--thinking in nothing but the pleasure Seulgi was able to give her, thinking about how Seulgi was so close to coming inside of her, just for her.

“Oh my god, I’m gonna come!” Seulgi moaned out desperately, really clinging to Joohyun’s hips and thrusting madly.  
  
Orgasm number nine and Seulgi’s first orgasm.

Seulgi’s massive cock expelled an equally massive quantity of her warm cream inside of Joohyun, filling her up to the brim, each desperate thrust squeezing more and more out of her balls. It was a long orgasm as well, even riding out Joohyun’s and starting her tenth one which was just as intense as the previous one. The cream oozed out of Joohyun’s pussy and dripped down to the bench, the cock bringing more before finally Seulgi’s long and intense orgasm faded away. And with that, Seulgi almost flopped on top of Joohyun’s body

The two of them were drained, Joohyun especially.

  
But fuck, wasn’t she happily drained?

  
  


**

  
  


Joohyun was fond of that gym, more so the staff that it had, and it was no secret to the people as to why. Some people had arrived a little later than Joohyun, mainly dudes who were pals with other trainers, and they heard the incessant sounds of sex all over the locker room.

Needless to say that every guy kept their hands off Joohyun as she trained, but of course there was that occasional new hotshot that approached.

He had heard of Joohyun and about her affair with one-shot Seulgi (a nickname, apparently) so he wanted to give it a shot for her to continue her sexual escapades.

Naturally, Joohyun didn’t even give him the benefit to say that she looked at him. She laughed and ignored. Wanting to bask in the aftermaths was purely pathetic. She would’ve accepted the offer though, as the aching between her legs was not satiated but intensified. After all, Seulgi never dipped in twice.

But she was different.

Seulgi had appeared and gotten close to Joohyun who had now stopped lifting her weights. With a very polite and charming smile, Seulgi speaks. “She’s with me.”

A smirk comes to Joohyun’s lips and the man instantly clears his throat and nods, turning back with disappointment and a bit of anger written all over his face.

Seulgi didn’t dip twice, but with Joohyun she has met her match.

And Joohyun’s husband has met her lawyer and the divorce papers.

  
  



End file.
